Saturday, November 16, 2013

Lately, comet ISON has been getting a lot of attention in the press and among astronomers, but at present it is difficult to see because it is close to the horizon just before dawn. Comet C/2013 R1 (Lovejoy), however, is considerably higher up in the early morning sky at my latitude. It reached naked eye visibility in early November.

Comets are named using a convention that indicates the type of comet, and the year, half-month and order in which it was discovered. The discoverer's name is often included, and is sometimes used as the familiar name for the comet. This comet was discovered in September 2013 by famous amateur astronomer Terry Lovejoy. It is a long-period comet, with an estimated orbital period of over 10,000 years.

I made these images early in the morning on November 13. The first is a stack made in RegiStax 5 of 16 two-minute exposures centered on the comet core. The comet was moving rather quickly, so over time it moved a significant distance within my camera's field of view. As a result, aligning the images on the comet core caused the stars to trail.

Sunday, September 29, 2013

I like finding objects that are close toone another in the sky like this interesting pair. Of course, they are many millions of light years apart from one another, but from our perspective they are neighbors. The spiral galaxy to the lower-left is cataloged as NGC 6946, but is more commonly known as the Fireworks Galaxy due to the unusually large number of supernovae recorded there in the past century. The Fireworks Galaxy is located along the border of the constellations Cepheus and Cygnus. Distance estimates vary between 10 and a little over 20 million light years away.

Open cluster NGC 6939 is considerably closer, at about 4000 light years, in the constellation Cepheus.

This is a difficult object to image due to its size. A patient person with enough time on his or her hands would do it in sections and build a mosaic. Not being particularly patient or possessing much time, I chose to do it in one series of shots. It barely fits within the field of view of my camera on the ST80; and since I do not have a field flattener there is a noticeable distortion on the edges. Still, I think this is my best one so far.

This is a wide-angle image of the Milky Way that roughly encompasses the area between the constellations Aquila (lower-left) to Scorpius (upper-right), taken during the night of the 2013 Perseid Meteor Shower from the SHSU observatory.

Monday, September 23, 2013

The road in front of my house runs east-west, so I thought I'd try one of those sunrise or sunset equinox pictures. Today was the first full day of autumn in East Texas. The sky was overcast at sunrise, but I was able to get these pictures about 20 minutes before sunset.

Saturday, August 17, 2013

I imaged Messier 16 back in July 2010, but was never satisfied with the results. It was one of my early attempts at imaging with the astrograph and the Canon EOS Rebel XS (1000D).

I've learned a lot about image processing since then and have gained better tools. So, occasionally I like to go back and rework older images to see if I can make them better. I'm satisfied enough with this image to post it, but I would like to go back and reshoot it one day when I get a chance.

Messier 16, also known as the Eagle Nebula, is perhaps most famous for the Hubble Space Telescope image of the Pillars of Creation. The pillars are visible in this image near the center, although they certainly don't look as spectacular here as in the Hubble image!

Wednesday, August 14, 2013

I went out to the Sam Houston State University observatory the night of August 12/13 to watch the Perseid meteor shower and try to catch a few on camera. The shower wasn't as active as I'd hoped, and as the night progressed some thin clouds rolled in; but, there were still quite a few really nice fireballs and several fainter meteors. Here are pictures from the event.

Meteors:

Meteor over the dome.

Perseid fireball.

Faint meteor right of center. The Andromeda Galaxy is the fuzzy patch located to the lower-right of the meteor, just above the power line.

Things that Looked Like Meteors, but were not Meteors:

I got really excited when I saw this bright streak on the camera preview, but after examining the images before and after I found that it was just a satellite. I have not been able to determine which satellite this is. Two more satellite trails are visible a little to the right of the streak at the bottom edge of the image.

I am uncertain about this little streak, which appears above the Milky Way in the constellation Ophiuchus. Its trajectory seems to point back in the direction of the Perseid radiant, but it may also be a flare from a satellite. The image was taken a little before 10:00 PM, which supports my satellite hypothesis since sunlight would still be shining over the horizon at the altitudes where many satellites orbit.

Other Shots:

This is the dome that houses the big telescope. The building to the left is the classroom. The streak on the left edge above the classroom building was created by an airplane's running lights.

There was a break in the clouds right along the line of sight with the Milky Way. I enhanced the Milky Way a bit in this image to bring out the detail.

Sunday, July 21, 2013

In my opinion summers in this part of East Texas are not great for astronomy. Most are hot, dry and hazy. Some are hot, rainy and cloudy. This summer has been the latter. The forecast shows clear skies for the coming week, but the moon will be right around the full phase. Maybe we'll have better astronomy weather next month. In the meantime, I'm keeping myself entertained with the clouds, of which there are plenty to see.
Here are some videos I made yesterday before, during and after a short rain shower.

Click on the images to load the videos. All of the videos are in Windows Media Video (WMV) format.

A cloud forms and dissipates from a column of rising air. I didn't have the camera set up correctly for this one, so the exposure times were variable, resulting in a sort of "blinking" effect. (2 MB)

Clouds form, a storm passes by. The big drops visible toward the end are from water dripping off of the roof. (7.8 MB)

Clouds forming after the rain. (2 MB)

You will probably notice a dot to the lower-right of center in all of these videos. I think there's a speck on my camera's imaging chip, but I have yet to find it.

Sunday, July 14, 2013

When life hands you lemons, make lemonade, right? Clouds are the bane of astronomers, unless you're doing radio astronomy. It has been very cloudy here on the edge of the Piney Woods lately. Still, I think clouds are fun to watch. Click on the image below to load a Windows Media Video of a cloud boiling away. The video compresses about 25 minutes into 15 seconds. The file is about 11.4 MB.

Wednesday, July 10, 2013

I was digging around in my archives and came across some images of Messier 24 from July 13, 2010. It occurred to me that Pluto would be somewhere within the image, and after some research and searching I managed to find it. It's the "star" at image center, indicated by the blue lines.

Sunday, July 7, 2013

The southern sky from my house is dominated by the light dome of Huntsville. One of the nice things about the Sam Houston State University observatory is its relatively dark southern sky; so, when I get a chance to image from the observatory I often image objects to the south.

During a recent visit to the observatory I imaged Messier 22, a globular cluster, and Messier 17, the Swan Nebula. Both objects are located in the constellation Sagittarius. Both images were made with my ST80 and the Vixen Super Polaris mount.

I was trying some experiments with a Barlow lens and apparently knocked the mount out of alignment. I didn't realize the problem until I started imaging Messier 17. I tried realigning it, but apparently didn't do something right. It was getting late and I was getting tired and making mistakes. However, I did manage to get five decent subs of the nebula.

Messier 17, the Swan Nebula; ST80 on a Vixen SP mount; 5x120

I've imaged Messier 17 before. I will definitely revisit this object when I get a chance.

Monday, July 1, 2013

For for those of you who are only interested in seeing the picture, here it is. Boring details about the imaging session are below. :)

Messier 5; ST80 on Vixen SP; 10x120 at ISO-800

Last night had nearly ideal viewing conditions, and I like to take any opportunity that I can to do some imaging or viewing, even if it's only for a short time. Fortunately the mount was already set up from the solar imaging session earlier that day, so I decided to work on improving my alignment skills.

Messier 5 was a good target for testing since it is fairly bright and was located near the celestial equator. As I've stated before, I use an old Vixen Super Polaris mount that was probably manufactured in the mid-1980s. The mount's polar alignment scope has an outdated reticle with a circle in which one is supposed to center Polaris. The circle is intersected by another circle that is drawn 48' from the center of the reticle, which represents the North Celestial Pole. The position of Polaris has changed significantly due to precession, so I've had to estimate where to place Polaris in relation to the markings on the reticle. Until last night my attempts have been anywhere from bad to not quite so bad.

I downloaded an app named Polar Finder for my Android phone. It features an iOptron reticle that makes it easy to pinpoint where Polaris should be in my Vixen finder scope. I estimated the location in the reticle, aligned the mount, and then took 23 two-minute exposures.

The results were pretty good! There was a little bit of drift, but the main problem was just periodic error, which I have no control over, anyway. The image below is a combination of all of the exposures made in Startrails. It illustrates how much the mount moved off target during the session.

23 images combined in Startrails, showing the effects of periodic error and misalignment.

The stars are streaked up and down due to periodic error. I expected to see something more like the oscillations captured during the 1998 QE2 imaging session, but apparently the alignment was very good. I think that the small "hook" to the right was due to vibration or wind affecting the mount. I'm looking forward to trying this again and taking long exposures on some galaxies and nebulae!

Sunday, June 30, 2013

It's been a while since I've done any solar imaging. I found that I enjoyed imaging in Hydrogen Alpha when I was preparing for the Venus Transit last year, but I don't have the right equipment. I borrowed a Coronado PST this weekend and managed to get a few images between the clouds.

All three images were made using the Coronado PST. The first two were imaged with a Meade DSI camera, and the third was imaged with a Canon EOS Rebel T3 (1100D). I was able to capture a separate set of images for the solar disk in the first image, which is why the details are more pronounced than in the second image.

Saturday, June 22, 2013

About once every 14 lunar months the Moon reaches perigee with the Earth at about the same time that it enters the Full phase. We call these events Supermoons. There's nothing intrinsically special about this occurrence. The Full Moon appears slightly larger than other Full Moons, and will be noticeably brighter to those who are used to seeing it often. But as far as its effects on Earth are concerned, there is very little to mention except that we humans like to make a big deal out of it.

Still, it's a good excuse to take pictures.

Here are a couple of snapshots taken of the 2013 Supermoon as it rose over the trees in my neighborhood. My neighbor across the street was kind enough to let me use her yard since the Moon is completely blocked from view in mine until it gets about 30 degrees above the horizon.

Thursday, June 20, 2013

I usually avoid taking pictures of the Moon with my ST80 because the scope's short focal length does not provide much magnification. I began experimenting with an adapter to use eyepiece projection, but could not bring anything into focus. I eventually discovered that a 2X barlow lens works fine with the adapter. Here are images of the Moon taken on June 20, 2013:

Sunday, June 9, 2013

Asteroid 1998 QE2 passed relatively close to Earth back on May 31, 2013. It remained relatively bright for several days after its closest approach, and I was able to capture it with my ST80 on June 3rd.

Below is a link to a movie composed of 100 30-second exposures made at ISO-6400 with my Canon EOS Rebel T3 (1100D). The exposures start at approximately 9:47 PM CDT and end around 11:09 PM CDT. The bright star near the bottom is Yed Posterior in Ophiucus. Several satellites can be seen streaking through the video.

I had to manually remove the effects of periodic error and bad polar alignment from each frame. The image below illustrates the effects of these errors over time. It is a combination of all 100 images compiled in Startrails. The up/down oscillation is due to periodic error, while the progression from left-to-right is the result of incorrect polar alignment. Autoguiding, Periodic Error Correction and various alignment techniques can reduce or remove these effects. Sadly, my mount does not support autoguiding or PEC.

The effects of periodic error (up/down oscillations) and misalignment (progression from left-to-right).

Thursday, June 6, 2013

I usually use a DSLR to capture lightning images, but this time I set up my Samsung Galaxy S III in the window at my office and caught a couple of strikes on video. I converted the MP4 video file to AVI and used VirtualDub to copy and paste the individual frames with lightning in them to Paint.NET to save them to files. The first strike was split up between a couple of frames, so I combined them using Startrails. Pretty cool for a phone, huh?

Look carefully where the bolt meets the ground and you can see the reflection of my hand in the window.

The reason I decided to post it here is to give an example of what a long exposure looks like on my new camera. I've had this camera for a while, but haven't had the opportunity to use it much for astrophotography. It is a Canon EOS Rebel T3 (1100D) that I got for cheap. It's main selling point was its low noise on long exposures. I was never able to separate the Flaming Star Nebula from the ambient noise of the old Rebel XS.

Another advantage of the new camera is that it will take exposures at ISO-3200 and ISO-6400, unlike the old camera that only went up to ISO-1600.

As those of you who keep up with this blog already know, I use an Orion ShortTube 80 on an old Vixen Super Polaris mount when I view and image from home. The Super Polaris is a great little mount, but it does not have autoguiding or any kind of fancy computer control, like GOTO. The polar alignment scope is out of date (it was probably made in the mid-80s), so I have to estimate where to place Polaris in the reticle. As a result, the best I can usually get out of it are 3-minute exposures. Therefore, I figure that the higher ISO and lower noise of the T3 will help me capture more detail.

Here is a portion a single shot from the run that was used to produce the image above. I limited the exposure time to two minutes because the light pollution was swamping the nebula at higher exposures.

Two-minute exposure at ISO-6400. The nebula is barely visible, but can be separated from the relatively even noise.

Here is another example frame. It is a portion of a shot of Messier 101:

Three-minute exposure at ISO-1600 of Messier 101.

I'm looking forward to trying this camera on the astrograph at the observatory.

Wednesday, May 29, 2013

I finally got a clear shot of the western sky to see the Mercury-Venus-Jupiter conjunction. This will be the closest grouping of these three planets until 2021.

Mercury is the faint "star" near the top-center of the image. Venus is the bright object near the center, and Jupiter is located below and slightly to the left of Venus.

Mercury (top), Venus (center) and Jupiter, May 29, 2013.

I was in the back corner of my yard taking pictures when the sprinklers went off. One sprinkler head was about 10 feet away. Out of it's nearly 360 degree field of rotation, guess exactly where it was pointing when it went off... Luckily the camera only got a glancing blow.

Wednesday, March 13, 2013

Comet PANSTARRS is getting harder to see from my location. Tonight's images are probably the last that I will take. I missed the opportunity last night to get a shot of the comet with the Moon, so I tried to make up for that tonight:

Tuesday, March 12, 2013

My wife and I went up to the roof the Sam Houston State University parking garage to see the comet and take some pictures. A small crowd gathered around the telescope. Everyone seemed to have a good time. Below are some of the pics from tonight.

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About Me

I am an amateur astronomer living on the edge of the Piney Woods near Huntsville, TX. In addition to my own modest telescopes, I have access to a Takahashi Epsilon-200 that I regularly use for imaging. Most of the images on this blog were taken using either a Canon EOS Rebel XS (1000D) or T3 (1100D) DSLR mounted on the Epsilon-200, but I also image using an inexpensive Orion ShortTube 80 on a Vixen Super Polaris mount.